1. Field of the Invention
The present invention relates to a print apparatus using a continuous sheet.
2. Description of the Related Art
Japanese Patent Laid-Open No. 2005-305712 discloses a print apparatus that sequentially prints a plurality of images on a continuous sheet. This print apparatus is provided with a density sensor (35) that measures an ink density of an image on a downstream of a print head (H), a cut position sensor (41) on a downstream thereof, and a cutter (40). By using the print head, together with the plurality of images, a cutter mark is recorded in a margin area between adjacent images, and the sheet is cut for each image on the basis of a cut mark detection by the cut mark sensor. The finished print product thus cut for each image is generated.
In a field such as a photograph album binding, a single print apparatus desirably prints on both sides of a continuous sheet at a high speed and with a high quality. When a plurality of sheets where the duplex printing is performed are bungled and bound, the sizes of the respective sheets are necessarily matched with each other accurately. However, the apparatus described in Japanese Patent Laid-Open No. 2005-305712 is only supposed to perform a print on one face of the sheet. In view of the above, a problem that can be resolved by the present invention resides in how duplex printing can be performed at a high speed and with a high quality and also the sheet can be cut for each piece at a high positional accuracy to generate finished print products.
Also, in the apparatus described in Japanese Patent Laid-Open No. 2005-305712, when the sheet is cut by the cutter, it is necessary to temporarily stop the sheet conveyance at the cut position. Then, a slight impact accompanied by the stop of the sheet is transmitted to the sheet upstream side, and the sheet is slightly displaced, which may affect the reading accuracy at the density sensor and the print accuracy at the print head. In a case where the margin area is provided between the adjacent images as in Japanese Patent Laid-Open No. 2005-305712, after the cut mark is detected, the margin area is unnecessary. Thus, the margin area is cut off by the cutter. In order to cut off the margin area, as the cut is continuously performed twice at two locations including a front end and a rear end of the margin area, and therefore the sheet is continuously stopped twice. For this reason, the impact is transmitted twice to the sheet upstream side, which affects the reading accuracy of the density sensor or the print accuracy of the print head to some extent. Another problem that can be resolved by the present invention resides in how this influence can be diminished.
Also, in the apparatus described in Japanese Patent Laid-Open No. 2005-305712, when the cut position sensor detects the sheet of the cut mark, the cut position sensor necessarily distinguishes the original image from the cut mark and correctly detects only the cut mark. However, if a pattern similar to the cut mark is accidentally included in the original image, this image is misidentified as the cut mark, and the sheet may be cut at a wrong position. Still another problem that can be resolved by the present invention resides in how such false recognition can be suppressed.